Numerous attempts have been made to provide lubricants having metal particles therein for the purpose of providing deposition of such metals on the metal bearing surfaces of engines to improve the lubricating qualities and especially the wear resistance of the lubricants. To date, none has been completely successful.
U.S. Pat. No. 3,894,957 is directed to a lubricating oil composition composed of finely divided particles of copper-lead alloy in powdered form in a carrier or base oil. Various ratios of copper to lead are set forth as contained in the alloy.
U.S. Pat. No. 3,532,623 shows the use of powdered copper or powdered lead in a dispersion medium wherein the metals are in the form of flakes.
U.S. Pat. No. 2,543,741 relates to lubricants which contain in combination, powdered copper, powdered lead and graphite. The copper particles are in the form of flakes and other shapes are disclosed as not being suitable.
U.S. Pat. No. 2,321,203 teaches various stabilizers for finely dispersed metals such as lead in lubricating compositions.
U.S. Pat. No. 2,160,911 shows greases containing colloidal lead.
U.S. Pat. No. 1,658,173 teaches lubricants containing copper or lead or zinc or other suitable metals as finely divided flocculent metal. The metals are disclosed as being of sponge form.
U.S. Pat. No. 269,636 teaches the use of an amalgam of mercury with copper and lead.
None of these prior art teachings is seen to teach applicant's novel lubricating composition.